Non-aqueous liquid anti-shrinkage cement additives

ABSTRACT

The present disclosure relates to a method of cementing comprising: providing a cement composition comprising: water, a cement, and a non-aqueous liquid anti-shrinkage cement additive comprising calcined magnesium oxide and a non-aqueous liquid; introducing the cement composition into a subterranean formation; and allowing the cement composition to set in the subterranean formation. Non-aqueous liquid anti-shrinkage cement additives, cement compositions, and systems are also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. application Ser. No. 16/080,884entitled “NON-AQUEOUS LIQUID ANTI-SHRINKAGE CEMENT ADDITIVES,” filed onAug. 29, 2018, now U.S. Patent. No. 10,737,978 which is a 35 U.S.C. §371 National Stage Entry of International Application No.PCT/US2016/033251 entitled “NON-AQUEOUS LIQUID ANTI-SHRINKAGE CEMENTADDITIVES,” filed on May 19, 2016, the disclosure of which isincorporated herein by reference.

BACKGROUND

In well cementing, such as well construction and remedial cementing,cement compositions are commonly utilized. Cement compositions may beused in a variety of subterranean applications. For example, insubterranean well construction, a pipe string (e.g., casing, liners,expandable tubulars, etc.) may be run into a well bore and cemented inplace. The process of cementing the pipe string in place is commonlyreferred to as “primary cementing.” In a typical primary cementingmethod, a cement composition may be pumped into an annulus between thewalls of the well bore and the exterior surface of the pipe stringdisposed therein. The cement composition may set in the annular space,thereby forming an annular sheath of hardened, substantially impermeablecement (i.e., a cement sheath) that may support and position the pipestring in the well bore and may bond the exterior surface of the pipestring to the subterranean formation. Among other things, the cementsheath surrounding the pipe string functions to prevent the migration offluids in the annulus, as well as protecting the pipe string fromcorrosion. Cement compositions also may be used in remedial cementingmethods, for example, to seal cracks or holes in pipe strings or cementsheaths, to seal highly permeable formation zones or fractures, to placea cement plug, and the like.

A particular challenge in well cementing is the development ofsatisfactory mechanical properties in a cement composition within areasonable time period after placement in the subterranean formation.During the life of a well, the cement sheath undergoes numerous strainsand stresses as a result of temperature effects, pressure effects, andimpact effects. The ability to withstand these strains and stresses isdirectly related to the mechanical properties of the settablecomposition after setting. The mechanical properties are oftencharacterized using parameters such as compressive strength, tensilestrength, Young's Modulus, Poisson's Ratio, elasticity, and the like.These properties may be modified by the inclusion of additives.

Conventional cement compositions have the limitation of shrinking duringcement hydration. The shrinkage of the cement composition may result inthe stresses that lead to damage of the cement sheath. The cement sheathmay de-bond from the casing or formation resulting in micro-annuli andcompromised zonal isolation. In some instances, such as certaincombinations of depth and formation properties, even when external fluidis available to fully hydrate the cement composition, the cement sheathmay become stressed during hydration and may not be able to withstandsubsequent well operations.

One additive used to enhance mechanical properties is an anti-shrinkadditive. The anti-shrink additive helps prevent premature failure ofthe cement sheath by inhibiting or preventing cracks from forming. Insome instances, cracks and gaps formed may lead to the migration of gasand fluid within the well and loss of zonal isolation. There may beconsiderable expense involved to repair a well with a failed cementsheath. In some instances the damage may be extensive enough to wherethe well needs to be abandoned.

BRIEF DESCRIPTION OF THE DRAWINGS

These drawings illustrate certain aspects of some of the embodiments ofthe present disclosure, and should not be used to limit or define themethod.

FIG. 1 is a schematic illustration of a system for preparation anddelivery of a cement composition to a wellbore in accordance withcertain examples.

FIG. 2A is a schematic illustration of surface equipment that may beused in placement of a cement composition in a wellbore in accordancewith certain examples.

FIG. 2B is a schematic illustration of placement of a cement compositioninto a wellbore annulus in accordance with certain examples.

DETAILED DESCRIPTION

The present disclosure relates to a non-aqueous liquid anti-shrinkagecement additive and, in specific examples, to methods, compositions, andsystems that use a non-aqueous liquid anti-shrinkage cement additive inwell cementing. By way of example the non-aqueous liquid anti-shrinkagecement additive may, without limitation, be used in Portland cement,pozzolan-lime cement, slag-lime cement, super sulfated cements, calciumsulfoaluminate cement, or geopolymer cements to reduce or eliminate theshrinkage associated with curing of the cement. As disclosed herein, an“anti-shrinkage cement additive” is defined to mean an additive thatwill cause a non-negative volumetric change in a cement composition asmeasured based on the tests and calculations in API RP 10B-5 at 190° F.and ambient pressure. Those of ordinary skill in the art will recognizethat the minimum concentration of a particular additive to cause apositive volumetric expansion will vary based on a number of factors,which may include the type of additive, the type of cement, andadditional additives present, among others.

There may be many factors that may lead to shrinking and cracking ofcement compositions. One of the most important factors may be totalwater content of the cement composition. When excess water separatesfrom a curing cement compound, a meniscus may set up within thecapillaries or pores of the cement. The high surface tension of thewater may cause a stress to be exerted on the internal walls of thecapillaries or pores wherein the meniscus may have formed. This stressmay be in the form of an inward pulling force that tends to close up thecapillary or pore. The volume of the capillary may thusly be reduced,leading to shrinkage of the cement composition, and resulting in anoverall reduction of volume. The addition of an anti-shrinkage additivemay eliminate the reduction in volume by exerting a swelling force oroutward pushing force on the cement composition.

Calcined magnesium oxide may be included in cement compositions as ananti-shrinkage additive. Calcined magnesium oxide may set to form ahardened mass upon reacting with water and may further react with othercomponents in the cement composition such as for example, a Portlandcement, to contribute to the final compressive strength of the cementcomposition. Calcined magnesium oxide may swell upon setting and exertan outward force on the cement composition. The swelling force maycontribute to a reduction in total shrinkage and in some instances, maycause an increase in total cement volume. Calcined magnesium oxide mayfurther scavenge free water within the cement composition, therebyreducing the amount of water available to exert an inward force.

There may be many advantages to using liquid additives in cementing.Liquid additives generally do not need to be mixed before use and may beeasier to store and transport than solid additives. Liquids may readilybe transported via tubulars and pumps which is particularly useful tooffshore applications where space may be limited. Liquid materials mayalso be required for regulatory purposes. For many operations, liquidadditives may reduce complexity of equipment needed as the additive cangenerally be pumped directly into mixing tubs or storage containers.Liquid additives may also eliminate dusting and complexities oftransporting and delivering dry additives in sacks or containers. Asliquids generally do not need to be mixed prior to combination withother cement components, equipment that would be used to mix solidadditives may be eliminated. Liquid additives volumes may generally beeasier to measure than dry additives and pre-mixed liquid additivesdelivered to a site may generally be more uniform in concentration thatwhat could be prepared on the fly at a location. The limited variabilityof liquid additives may make the cement compositions more uniform inquality and mechanical properties.

Calcined magnesium oxide may set to form a hardened mass in the presenceof water. Once the water and calcined magnesium oxide are mixed, theremay be a limited time window before the suspension becomes thick andun-pumpable. The limited pump time of the suspension makes it non-idealto store for extended periods of time. An aqueous suspension of calcinedmagnesium oxide would therefore not be ideal as a liquid additive sincethe suspension may set before it can be added to a cement slurry. Theuse of non-aqueous solvents as the suspending medium precludes thecalcined magnesium oxide from hydrating while in suspension. However, ithas been found that conventional oil suspensions do not provide adequaterheological stability either in the additive suspension or upon mixingthe additive suspension with cement. Conventional oil suspensionscomprising calcined magnesium oxide may result in a gelled additiveand/or gelation in a cement slurry upon introducing the additive to thecement slurry. The gelation can cause many undesirable effects includingbut not limited to poor mixing, reduced compressive strength, poor zonalisolation, and increased load and wear on equipment. For at least thesereasons, a non-aqueous liquid anti-shrinkage cement additive that doesnot exhibit gelling would be useful in well cementing.

Without limitation, the non-aqueous liquid anti-shrinkage cementadditive may comprise a non-aqueous fluid, a dispersant, a viscosifyingadditive, an emulsifying agent, and calcined magnesium oxide.

The non-aqueous fluid may comprise a hydrocarbon liquid. The hydrocarbonliquid may, without limitation, comprise alkanes, unsaturatedhydrocarbons such as alkenes and alkynes, cycloalkanes, aromatichydrocarbons, and any mixtures thereof. Hydrocarbon liquids may furthercomprise, without limitation, mixtures of hydrocarbons such as naturalgas liquids, liquid parrafins, naphthas, mineral oils, crude oils,synthesized hydrocarbon liquids, fuel oils, diesels, gasolines, biomassderived hydrocarbon liquids, coal derived hydrocarbon liquids, kerosene,and any mixtures thereof. Without limitation, the hydrocarbon liquid maybe present in an amount of about 1% to about 99% by weight in thenon-aqueous liquid anti-shrinkage cement additive. The hydrocarbonliquid may be present in an amount, for example, ranging between any ofand/or including any of about 5%, about 10%, about 15%, about 20%, about25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%,about 60%, about 65%, about 70%, about 75%, about 80%, about 90%, about95%, or about 99% by weight in the non-aqueous liquid anti-shrinkagecement additive.

The dispersant may comprise any of a variety of suitable compounds. Ingeneral, a dispersant should remain stable while suspended in thenon-aqueous solvent, enable the components of the non-aqueous liquidanti-shrinkage additive to be easily mixed and enable easy pumping,and/or reduce viscosity of a cement composition when the non-aqueousliquid anti-shrinkage additive is added. The dispersant, withoutlimitation, may comprise sulfonated naphthalene condensate, sulfonatedacetone formaldehyde condensate, polycarboxylate ethers, microparticles, or any combination thereof. An example of a dispersantadditive is available from Halliburton Energy Services Inc. under thetrade name CFR™-3 cement friction reducer. Without limitation, thedispersant may be present in an amount of about 0.01% to about 5% byweight in the non-aqueous liquid anti-shrinkage cement additive. Thedispersant may be present in an amount, for example, ranging between anyof and/or including any of about 0.01%, about 1%, about 2%, about 3%,about 4%, or about 5% by weight in the non-aqueous liquid anti-shrinkagecement additive.

The viscosifying additive may comprise any of a variety of suitablecompounds. In general, a viscosifying additive should be able toincrease and maintain the viscosity of oleaginous liquids, and maintaina stable suspension with solids. The viscosifying additive, withoutlimitation, may comprise organophilic clay or other suitable hydrocarbonthickeners, such as hydrophobically modified silica, hydrophobicallymodified bio-polymers, and hydrophobically modified synthetic polymers.An example of an organophilic clay is available from Halliburton EnergyServices, Inc. under the trade name Claytone® II rheological additive.Without limitation, the viscosifying additive may be present in anamount of about 0.01% to about 10% by weight in the non-aqueous liquidanti-shrinkage cement additive. The viscosifying additive may be presentin an amount, for example, ranging between any of and/or including anyof about 0.01%, about 1%, about 2%, about 3%, about 4%, about 5%, about6%, about 7%, about 8%, about 9%, or about 10% by weight in thenon-aqueous liquid anti-shrinkage cement additive.

The emulsifying agent may comprise any of a variety of suitablecompounds. The emulsifying agent may be hydrophilic or hydrophobic innature. In some examples, the emulsifying agent may comprise bothhydrophilic and hydrophobic compounds. Hydrophilic emulsifiers maycomprise, without limitation, polysorbates. Hydrophobic emulsifiers maycomprise, without limitation, sorbitan esters. Without limitation, theemulsifying agent may be present in an amount of about 0.01% to about10% by weight in the non-aqueous liquid anti-shrinkage cement additive.The emulsifying agent may be present in an amount, for example, rangingbetween any of and/or including any of about 0.01%, about 1%, about 2%,about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, orabout 10% by weight in the non-aqueous liquid anti-shrinkage cementadditive.

The non-aqueous liquid anti-shrinkage cement additive may comprisecalcined magnesium oxide (MgO). Calcined magnesium oxide may beproduced, for example, by the calcination of naturally occurringminerals such as magnesite which has the chemical formula MgCO₃ andmagnesium hydroxide Mg(OH)₂. Calcination is the process of heating acompound at elevated temperature to affect desirable properties. Thethermal treatment of calcination affects the surface area and pore sizeand hence the reactivity of magnesium oxide formed. Caustic calcinedmagnesia (light burned magnesium oxide) may be produced by calcining inthe range of 700° C. to 1000° C. Calcining in the range of 1500° C. to2000° C. produces dead-burned magnesium oxide. The degree of calcinationmay impact the operating temperature window of the additive. Forexample, dead-burned magnesium oxide may be used at higher operatingtemperatures than light-burned magnesium oxide owning to a greateramount of thermal energy needed to induce reactivity. An example ofmagnesium oxide additive is available from Halliburton Energy ServicesInc. under the trade name Microbond HT™ expanding additive. The calcinedmagnesium oxide may be present in any amount from about 1% to about 99%by weight of the non-aqueous liquid anti-shrinkage cement additive. Thecalcined magnesium oxide may be present in an amount, for example,ranging between any of and/or including any of about 5%, about 10%,about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%,about 80%, about 90%, about 95%, or about 99% by weight in thenon-aqueous liquid anti-shrinkage cement additive.

The non-aqueous liquid anti-shrinkage cement additive may be prepared byany suitable means. In some examples, the cement additive may beprepared by measuring a pre-determined amount of each of the liquidcomponents into a container. The liquid components may comprise thenon-aqueous liquid, dispersant, and/or emulsifying agents. Thenon-aqueous liquid and other liquid components may be sheared until ahomogenous solution is obtained. A pre-determined amount of solidadditives may be added to the container. The solid additives maycomprise the viscosifying additive and/or calcined magnesium oxide. Thesolution may be further sheared until the solid particles are uniformlydispersed. The resulting solid-in-oil suspension may be stored for anextended period of time such as about 1 day to about 1 year.

A cement composition suitable for well cementing may comprise thenon-aqueous liquid anti-shrinkage additive. Without limitation, thecement composition may comprise cement, non-aqueous liquidanti-shrinkage cement additive, and water. Those of ordinary skill inthe art will appreciate that the cement compositions generally shouldhave a density suitable for a particular application. By way of example,the cement composition may have a density in the range of from about 4pounds per gallon (“lb/gal”) to about 20 lb/gal and, in somecompositions, a density in the range of from about 8 lb/gal to about 17lb/gal. The cement compositions may be foamed or unfoamed or maycomprise other means to reduce their densities, such as hollowmicrospheres, low-density elastic beads, or other density-reducingadditives known in the art. Those of ordinary skill in the art, with thebenefit of this disclosure, should recognize the appropriate density fora particular application.

Any of a variety of cements suitable for use in subterranean cementingoperations may be used in the disclosed cement compositions. Suitableexamples may include hydraulic cements that comprise calcium, aluminum,silicon, oxygen and/or sulfur, which set and harden by reaction withwater. Such hydraulic cements, include, but are not limited to, Portlandcements, pozzolana cements, gypsum cements, high-alumina-contentcements, slag cements, silica cements, geopolymer cements andcombinations thereof. Without limitation, the hydraulic cement maycomprise a Portland cement. Without limitation, Portland cements thatmay be suited for use may be classified as Class A, C, H and G cementsaccording to American Petroleum Institute, API Specification forMaterials and Testing for Well Cements, API Specification 10, Fifth Ed.,Jul. 1, 1990. In addition, in some embodiments, hydraulic cementssuitable for use may be classified as ASTM Type I, II, or III. Withoutlimitation, the cement may be present in the cement compositions in anamount in the range of from about 10% to about 80% by weight of thecement composition. The cement may be present in an amount, for example,ranging between any of and/or including any of about 10%, about 20%,about 30%, about 40%, about 50%, about 60%, about 70%, or about 80% byweight of the cement composition. One of ordinary skill in the art, withthe benefit of this disclosure, should be able to select an appropriateamount of cement for a particular application.

Without limitation, the water used in the cement compositions may befresh water or salt water. As used herein, the term “salt water” refersto unsaturated salt water and saturated salt water, including brines andseawater. Generally, the water may be from any source, provided that itshould not contain an excess of compounds that may undesirably affectother components in the foamed cement composition. Further, the watermay be present in an amount sufficient to form a pumpable slurry.Without limitation, the water may be present in the cement compositionin an amount in the range of about 33% to about 200% by weight of thecement (“bwoc”). For example, the water may be present in the cementcomposition in the range of about 35% to about 70% bwoc. Alternatively,the concentration of the water may be expressed by weight over theoverall cement composition, such from about 20% to about 80% by weightof the cement composition, including about 20%, about 30%, about 40%,about 50%, about 60%, about 70%, or about 80% by weight of the cementcomposition. One of ordinary skill in the art with the benefit of thisdisclosure should recognize the appropriate amount of water for a chosenapplication.

Without limitation, the non-aqueous liquid anti-shrinkage cementadditive may be included in the cement composition in an amount in therange of about 0.01% to about 10% bwoc. For example, the non-aqueousliquid anti-shrinkage cement additive may be present in the cementcomposition in the range of about 1% to about 5% bwoc. Alternatively,the concentration of the non-aqueous liquid anti-shrinkage cementadditive may be expressed by weight over the overall cement composition,such from about 0.01% to about 5% by weight of the cement composition,including about 1%, about 2%, about 3%, about 4%, or about 5% by weightof the cement composition. One of ordinary skill in the art with thebenefit of this disclosure should recognize the appropriate amount ofnon-aqueous liquid anti-shrinkage cement additive for a chosenapplication.

Other additives suitable for use in subterranean cementing operationsalso may be added to the cement compositions as desired for a particularapplication. Examples of such additives include, but are not limited to,strength-retrogression additives, set accelerators, set retarders,weighting agents, lightweight additives, gas-generating additives,mechanical property enhancing additives, lost-circulation materials,filtration-control additives, dispersants, a fluid loss controladditive, defoaming agents, foaming agents, thixotropic additives, andcombinations thereof. By way of example, the cement composition may be afoamed cement composition further comprising a foaming agent and a gas.Specific examples of these, and other, additives include crystallinesilica, amorphous silica, fumed silica, salts, fibers, hydratable clays,calcined shale, vitrified shale, microspheres, fly ash, slag,diatomaceous earth, metakaolin, rice husk ash, natural pozzolan,zeolite, lime, elastomers, resins, latex, combinations thereof, and thelike. A person having ordinary skill in the art, with the benefit ofthis disclosure, will readily be able to determine the type and amountof additive useful for a particular application and desired result.

As will be appreciated by those of ordinary skill in the art, thenon-aqueous liquid anti-shrinkage cement additive may be used in avariety of subterranean applications, including primary and remedialcementing. Without limitation, the cement compositions comprising thenon-aqueous liquid anti-shrinkage cement additive may be introduced intoa subterranean formation and allowed to set. As used herein, introducingthe cement composition into a subterranean formation includesintroduction into any portion of the subterranean formation, into nearwellbore region surrounding the wellbore, or into both. In primarycementing applications, for example, the cement compositions may beintroduced into the annular space between a conduit located in awellbore and the walls of the wellbore (and/or a larger conduit in thewellbore), wherein the wellbore penetrates the subterranean formation.The cement composition may be allowed to set in the annular space toform an annular sheath of hardened cement. The cement composition mayform a barrier that prevents the migration of fluids in the wellbore.The cement composition may also, for example, support the conduit in thewellbore. In remedial cementing applications, the cement compositionsmay be used, for example, in squeeze cementing operations or in theplacement of cement plugs. By way of example, the cement compositionsmay be placed in a wellbore to plug an opening (e.g., a void or crack)in the formation, in a gravel pack, in the conduit, in the cementsheath, and/or between the cement sheath and the conduit (e.g., amicroannulus).

Without limitation, an example method of cementing may compriseproviding a cement composition comprising: water, a cement, and anon-aqueous liquid anti-shrinkage cement additive comprising calcinedmagnesium oxide and a non-aqueous liquid; introducing the cementcomposition into a subterranean formation; and allowing the cementcomposition to set in the subterranean formation. This method ofcementing may include any of the various features of the additives,compositions, methods, and systems disclosed herein. The non-aqueousliquid may comprise a hydrocarbon liquid. Without limitation, thenon-aqueous liquid anti-shrinkage cement additive may further comprise adispersant selected from the group consisting of sulfonated naphthalenecondensate, sulfonated acetone formaldehyde condensate, polycarboxylateethers, micro particles, and any combination thereof. The non-aqueousliquid anti-shrinkage cement additive may further comprise aviscosifying additive. The non-aqueous liquid anti-shrinkage cementadditive may further comprise an emulsifying additive. The non-aqueousliquid anti-shrinkage cement additive may further comprise a dispersantand an emulsifying additive, wherein the method further comprisesproviding the non-aqueous liquid anti-shrinkage cement additive andcombining the non-aqueous liquid anti-shrinkage cement additive with thewater and the cement.

Without limitation, an example of a non-aqueous liquid anti-shrinkagecement additive may comprise: a non-aqueous liquid; and calcinedmagnesium oxide. This non-aqueous liquid anti-shrinkage cement additivemay include any of the various features of the additives, compositions,methods, and systems disclosed herein. The non-aqueous liquid maycomprise a hydrocarbon liquid. The non-aqueous liquid anti-shrinkagecement additive may further comprise a dispersant selected from thegroup consisting of sulfonated naphthalene condensate, sulfonatedacetone formaldehyde condensate, polycarboxylate ethers, microparticles, and any combination thereof. The non-aqueous liquidanti-shrinkage cement additive may further comprise a viscosifyingadditive. The non-aqueous liquid anti-shrinkage cement additive mayfurther comprise an emulsifying additive.

Without limitation, an example of a cement composition may comprise acement composition comprising water; a cement; and a non-aqueous liquidanti-shrinkage cement additive comprising calcined magnesium oxide and anon-aqueous liquid. This cement composition may include any of thevarious features of the additives, compositions, methods, and systemsdisclosed herein. The non-aqueous liquid may comprise a hydrocarbonliquid. The non-aqueous liquid anti-shrinkage cement additive mayfurther comprise a dispersant selected from the group consisting ofsulfonated naphthalene condensate, sulfonated acetone formaldehydecondensate, polycarboxylate ethers, micro particles, and any combinationthereof. The non-aqueous liquid anti-shrinkage cement additive mayfurther comprise a viscosifying additive. The non-aqueous liquidanti-shrinkage cement additive may further comprise an emulsifyingadditive.

Without limitation, an example of a system for cementing in asubterranean formation comprising: a cement composition comprising acement, water, a non-aqueous liquid anti-shrinkage cement additive,wherein the non-aqueous liquid anti-shrinkage cement additive comprisescalcined magnesium oxide and a non-aqueous liquid; mixing equipmentcapable of mixing the cement composition; and pumping equipment capableof delivering the cement composition into a wellbore. This system mayinclude any of the various features of the additives, compositions,methods, and systems disclosed herein. The non-aqueous liquid maycomprise a hydrocarbon liquid. The non-aqueous liquid anti-shrinkagecement additive may further comprise a dispersant selected from thegroup consisting of sulfonated naphthalene condensate, sulfonatedacetone formaldehyde condensate, polycarboxylate ethers, microparticles, and any combination thereof. The non-aqueous liquidanti-shrinkage cement additive may further comprise a viscosifyingadditive. The non-aqueous liquid anti-shrinkage cement additive mayfurther comprise an emulsifying additive.

Referring now to FIG. 1, preparation of a cement composition comprisinga non-aqueous liquid anti-shrinkage cement additive in accordance withexample systems, methods and cement compositions will now be described.FIG. 1 illustrates a system 2 for preparation of a cement compositionand delivery to a wellbore in accordance with certain systems, methodsand cement compositions. As shown, the cement composition may be mixedin mixing equipment 4, such as a jet mixer, re-circulating mixer, or abatch mixer, for example, and then pumped via pumping equipment 6 to thewellbore. In some systems, methods and compositions, the mixingequipment 4 and the pumping equipment 6 may be disposed on one or morecement trucks as will be apparent to those of ordinary skill in the art.

An example technique for placing a cement composition comprising anon-aqueous liquid anti-shrinkage additive, as described herein, into asubterranean formation will now be described with reference to FIGS. 2Aand 2B. FIG. 2A illustrates surface equipment 10 that may be used inplacement of a cement composition. It should be noted that while FIG. 2generally depicts a land-based operation, those skilled in the art willreadily recognize that the principles described herein are equallyapplicable to subsea operations that employ floating or sea-basedplatforms and rigs, without departing from the scope of the disclosure.As illustrated by FIG. 2A, the surface equipment 10 may include acementing unit 12, which may include one or more cement trucks. Thecementing unit 12 may include mixing equipment 4 and pumping equipment 6(e.g., FIG. 1) as will be apparent to those of ordinary skill in theart. The cementing unit 12 may pump a cement composition 14 through afeed pipe 16 and to a cementing head 18 which conveys the cementcomposition 14 downhole

Turning now to FIG. 2B, the cement composition 14 may be placed into asubterranean formation 20 in accordance with example systems, methodsand cement compositions. As illustrated, a wellbore 22 may be drilledinto the subterranean formation 20. While wellbore 22 is shown extendinggenerally vertically into the subterranean formation 20, the principlesdescribed herein are also applicable to wellbores that extend at anangle through the subterranean formation 20, such as horizontal andslanted wellbores. As illustrated, the wellbore 22 comprises walls 24.In the illustration, a surface casing 26 has been inserted into thewellbore 22. The surface casing 26 may be cemented to the walls 24 ofthe wellbore 22 by cement sheath 28. In the illustration, one or moreadditional conduits (e.g., intermediate casing, production casing,liners, etc.), shown here as casing 30 may also be disposed in thewellbore 22. As illustrated, there is a wellbore annulus 32 formedbetween the casing 30 and the walls 24 of the wellbore 22 and/or thesurface casing 26. One or more centralizers 34 may be attached to thecasing 30, for example, to centralize the casing 30 in the wellbore 22prior to and during the cementing operation.

With continued reference to FIG. 2B, the cement composition 14 may bepumped down the interior of the casing 30. The cement composition 14 maybe allowed to flow down the interior of the casing 30 through the casingshoe 42 at the bottom of the casing 30 and up around the casing 30 intothe wellbore annulus 32. The cement composition 14 may be allowed to setin the wellbore annulus 32, for example, to form a cement sheath thatsupports and positions the casing 30 in the wellbore 22. While notillustrated, other techniques may also be utilized for introduction ofthe cement composition 14. By way of example, reverse circulationtechniques may be used that include introducing the cement composition14 into the subterranean formation 20 by way of the wellbore annulus 32instead of through the casing 30.

As it is introduced, the cement composition 14 may displace other fluids36, such as drilling fluids and/or spacer fluids that may be present inthe interior of the casing 30 and/or the wellbore annulus 32. At least aportion of the displaced fluids 36 may exit the wellbore annulus 32 viaa flow line 38 and be deposited, for example, in one or more retentionpits 40 (e.g., a mud pit), as shown on FIG. 2A. Referring again to FIG.2B, a bottom plug 44 may be introduced into the wellbore 22 ahead of thecement composition 14, for example, to separate the cement composition14 from the fluids 36 that may be inside the casing 30 prior tocementing. After the bottom plug 44 reaches the landing collar 46, adiaphragm or other suitable device should rupture to allow the cementcomposition 14 through the bottom plug 44. In FIG. 2B, the bottom plug44 is shown on the landing collar 46. In the illustration, a top plug 48may be introduced into the wellbore 22 behind the cement composition 14.The top plug 48 may separate the cement composition 14 from adisplacement fluid 50 and also push the cement composition 14 throughthe bottom plug 44.

The exemplary cement compositions disclosed herein may directly orindirectly affect one or more components or pieces of equipmentassociated with the preparation, delivery, recapture, recycling, reuse,and/or disposal of the disclosed cement compositions. For example, thedisclosed cement compositions may directly or indirectly affect one ormore mixers, related mixing equipment, mud pits, storage facilities orunits, composition separators, heat exchangers, sensors, gauges, pumps,compressors, and the like used generate, store, monitor, regulate,and/or recondition the exemplary cement compositions. The disclosedcement compositions may also directly or indirectly affect any transportor delivery equipment used to convey the cement compositions to a wellsite or downhole such as, for example, any transport vessels, conduits,pipelines, trucks, tubulars, and/or pipes used to compositionally movethe cement compositions from one location to another, any pumps,compressors, or motors (e.g., topside or downhole) used to drive thecement compositions into motion, any valves or related joints used toregulate the pressure or flow rate of the cement compositions, and anysensors (i.e., pressure and temperature), gauges, and/or combinationsthereof, and the like. The disclosed cement compositions may alsodirectly or indirectly affect the various downhole equipment and toolsthat may come into contact with the cement compositions such as, but notlimited to, wellbore casing, wellbore liner, completion string, insertstrings, drill string, coiled tubing, slickline, wireline, drill pipe,drill collars, mud motors, downhole motors and/or pumps, cement pumps,surface-mounted motors and/or pumps, centralizers, turbolizers,scratchers, floats (e.g., shoes, collars, valves, etc.), logging toolsand related telemetry equipment, actuators (e.g., electromechanicaldevices, hydromechanical devices, etc.), sliding sleeves, productionsleeves, plugs, screens, filters, flow control devices (e.g., inflowcontrol devices, autonomous inflow control devices, outflow controldevices, etc.), couplings (e.g., electro-hydraulic wet connect, dryconnect, inductive coupler, etc.), control lines (e.g., electrical,fiber optic, hydraulic, etc.), surveillance lines, drill bits andreamers, sensors or distributed sensors, downhole heat exchangers,valves and corresponding actuation devices, tool seals, packers, cementplugs, bridge plugs, and other wellbore isolation devices, orcomponents, and the like.

To facilitate a better understanding of the present disclosure, thefollowing examples of certain aspects of some of the systems, methodsand cement compositions are given. In no way should the followingexamples be read to limit, or define, the entire scope of thedisclosure.

Example 1

This example provides a formative comparison of non-aqueous liquidanti-shrinkage additives with (I) and without (II) dispersant, andrheology measurements for the two. The rheology measurements were takenwith a FANN® 35 viscometer and are reported in centipoise. Claytone® IIrheological additive is an organophilic clay available from HalliburtonEnergy Services, Inc. which acts as a viscosifying additive. Polysorbateis a hydrophilic emulsifier and sorbitan ester is a hydrophobicemulsifier. CFR-3′ cement friction reducer is a dual purpose cementfriction reducer and dispersant available from Halliburton EnergyServices, Inc. In the following table, “% bw” refers to percent of thecomponent by weight of the overall non-aqueous liquid anti-shrinkageadditive.

TABLE 1 Material I (% bw) II (% bw) Mineral Oil 53.85 53.68 Claytone ®II 3.75 3.98 Rheological Additive Polysorbate 2.4 — Sorbitan Ester —1.59 Calcined MgO 40 39.76 CFR-3 ™ Cement — 0.99 Friction Reducer Total100 100 Ave Rheology of Additive 300 rpm 300 242 200 rpm 290 187 100 rpm186 118 60 rpm 137 76 30 rpm 92 46 6 rpm 46 30 3 rpm 36 24

Example 2

This example provides a comparison between cement compositions mixedwith non-aqueous liquid anti-shrinkage additives from Example 1 that didnot contain (III) and did contain (IV) dispersant. D-Air 3000L™ defoameravailable from Halliburton Energy Services, Inc. was included in eachcement composition. The viscosity measurements were taken on a FANN® 35viscometer with the viscosities reported in centipoise. Slurry III wasprepared without dispersant was unmixable. The slurry increased inviscosity to form a gel and was unable to be tested further. In thetable below, “gal/sk” refers to gallons of the additive per 94 poundsack of the cement.

TABLE 2 Material III IV Class H Premium Cement 100 % bwoc 100 % bwoc I1.12 gal/sk — — II — — 1.12 gal/sk Defoamer 0.02 gal/sk 0.02 gal/skWater 3.7 gal/sk 3.7 gal/sk Total 100 100 Ave Rheology of Cement +Additive 300 rpm Unmixable without 242 200 rpm the assistance of 201 100rpm a spatula, and was 153 60 rpm paste after mixing. 110 30 rpm Norheology 82 6 rpm measurements could 34 3 rpm be collected. 24

Example 3

This example provides a comparison between different cement compositionsand the expansion performance over time. Table 3 shows the three cementcompositions that were prepared. Slurry V contains a conventional dryexpansion additive calcined magnesium oxide. Slurry VI contains arepresentative non-aqueous calcined magnesium oxide provided in anon-aqueous liquid anti-shrinkage additive. Slurry VII contains noexpansion additive. D-Air 3000L™ defoamer available from HalliburtonEnergy Services, Inc. was included in each cement composition. Cementcompositions V-VII were subjected to ring mold expansion tests accordingto API RP 10B-5, cured at 190° F. at ambient pressure in a recirculatingwater bath. Table 4 shows the results of the test. In the table below,“gal/sk” refers to gallons of the additive per 94 pound sack of thecement.

TABLE 3 V VI VII Class H 100 % bwoc 100 % bwoc 100 % bwoc Cement DryCalcined 5 % bwoc — — — — MgO Non-Aqueous — — 1.15 gal/sk — — CalcinedMgO Defoamer 0.02 gal/sk 0.02 gal/sk 0.02 gal/sk Tap Water 4.81 gal/sk4.81 gal/sk 4.81 gal/sk

TABLE 4 % Expansion Curing Time (days) 1 3 6 9 12 V 0 0.06 0.589 2.0463.357 VI 0 0.211 1.665 2.966 3.765 VII 0 −0.01 −0.013 −0.021 −0.017

It should be understood that the compositions and methods are describedin terms of “comprising,” “containing,” or “including” variouscomponents or steps, the compositions and methods can also “consistessentially of” or “consist of” the various components and steps.Moreover, the indefinite articles “a” or “an,” as used in the claims,are defined herein to mean one or more than one of the element that itintroduces.

For the sake of brevity, only certain ranges are explicitly disclosedherein. However, ranges from any lower limit may be combined with anyupper limit to recite a range not explicitly recited, as well as, rangesfrom any lower limit may be combined with any other lower limit torecite a range not explicitly recited, in the same way, ranges from anyupper limit may be combined with any other upper limit to recite a rangenot explicitly recited. Additionally, whenever a numerical range with alower limit and an upper limit is disclosed, any number and any includedrange falling within the range are specifically disclosed. Inparticular, every range of values (of the form, “from about a to aboutb,” or, equivalently, “from approximately a to b,” or, equivalently,“from approximately a-b”) disclosed herein is to be understood to setforth every number and range encompassed within the broader range ofvalues even if not explicitly recited. Thus, every point or individualvalue may serve as its own lower or upper limit combined with any otherpoint or individual value or any other lower or upper limit, to recite arange not explicitly recited.

Therefore, the present embodiments are well adapted to attain the endsand advantages mentioned as well as those that are inherent therein. Theparticular embodiments disclosed above are illustrative only, and may bemodified and practiced in different but equivalent manners apparent tothose skilled in the art having the benefit of the teachings herein.Although individual embodiments are discussed, the disclosure covers allcombinations of all of the embodiments. Furthermore, no limitations areintended to the details of construction or design herein shown, otherthan as described in the claims below. Also, the terms in the claimshave their plain, ordinary meaning unless otherwise explicitly andclearly defined by the patentee. It is therefore evident that theparticular illustrative embodiments disclosed above may be altered ormodified and all such variations are considered within the scope andspirit of those embodiments. If there is any conflict in the usages of aword or term in this specification and one or more patent(s) or otherdocuments that may be incorporated herein by reference, the definitionsthat are consistent with this specification should be adopted.

What is claimed is:
 1. A cement composition comprising: water; a cement;and a suspension of calcined magnesium oxide in a hydrocarbon liquid. 2.The composition of claim 1 wherein the calcined magnesium oxide ispresent in an amount of about 1% to about 50% by weight in thesuspension.
 3. The composition of claim 1 wherein the hydrocarbon liquidis selected from the group consisting of natural gas liquids, liquidparrafins, naphthas, mineral oils, crude oils, synthesized hydrocarbonliquids, fuel oils, diesels, gasolines, biomass derived hydrocarbonliquids, coal derived hydrocarbon liquids, kerosene, or combinationsthereof.
 4. The composition of claim 1 wherein the suspension furthercomprises a dispersant selected from the group consisting of sulfonatednaphthalene condensate, sulfonated acetone formaldehyde condensate,polycarboxylate ethers, or combinations thereof wherein the dispersantis present in an amount of about 0.01% to about 5% by weight in thesuspension.
 5. The composition of claim 1 wherein the suspension furthercomprises a viscosifying additive selected from the group consisting oforganophilic clay, hydrophobically modified silica, hydrophobicallymodified bio-polymers, hydrophobically modified synthetic polymers, orcombinations thereof wherein the viscosifying additive is present in anamount of about 0.01% to about 10% by weight in the suspension.
 6. Thecomposition of claim 1 wherein the suspension further comprises anemulsifying additive comprising a polysorbate, sorbitan esters, orcombinations thereof wherein the emulsifying additive is present in anamount of about 0.01% to about 10% by weight in the suspension.
 7. Thecomposition of claim 1 wherein the suspension is present in an amount ofabout 0.01% to about 10% by weight of the cement.
 8. A non-aqueousliquid anti-shrinkage cement additive comprising: a non-aqueous liquid;calcined magnesium oxide; and a viscosifying additive selected from thegroup consisting of organophilic clay, hydrophobically modified silica,hydrophobically modified bio-polymers, hydrophobically modifiedsynthetic polymers, or combinations thereof wherein the viscosifyingadditive is present in an amount of about 0.01% to about 10% by weightin the suspension.
 9. The additive of claim 8 wherein the non-aqueousliquid comprises a hydrocarbon liquid.
 10. The additive of claim 8further comprising a dispersant.
 11. The additive of claim 10 whereinthe dispersant selected from the group consisting of sulfonatednaphthalene condensate, sulfonated acetone formaldehyde condensate,polycarboxylate ethers, and any combination thereof.
 12. The additive ofclaim 8 further comprising an emulsifying additive comprising apolysorbate, sorbitan esters, or combinations thereof wherein theemulsifying additive is present in an amount of about 0.01% to about 10%by weight in the suspension.
 13. A method of preparing a non-aqueousliquid anti-shrinkage cement additive, the method comprising: providingcalcined magnesium oxide and a non-aqueous liquid comprising ahydrocarbon liquid; adding the calcined magnesium oxide and anon-aqueous liquid to a container to form a mixture; and shearing themixture until a homogenous solution is obtained.
 14. The method of claim13 wherein the calcined magnesium oxide is present in an amount of about1% to about 50% by weight in the mixture.
 15. The method of claim 13wherein calcined magnesium oxide is at least one or light burnedmagnesium oxide or dead-burned magnesium oxide.
 16. The method of claim13 wherein the hydrocarbon liquid is selected from the group consistingof natural gas liquids, liquid parrafins, naphthas, mineral oils, crudeoils, synthesized hydrocarbon liquids, fuel oils, diesels, gasolines,biomass derived hydrocarbon liquids, coal derived hydrocarbon liquids,kerosene, or combinations thereof.
 17. The method of claim 16 whereinthe viscosifying additive is present in an amount of about 0.01% toabout 10% by weight in the mixture.
 18. The method of claim 13 whereinthe mixture further comprises an emulsifying additive comprising apolysorbate, sorbitan esters, or combinations thereof.
 19. The method ofclaim 18 wherein the emulsifying additive is present in an amount ofabout 0.01% to about 10% by weight in the mixture.
 20. The method ofclaim 13 wherein the mixture further comprises a dispersant selectedfrom the group consisting of sulfonated naphthalene condensate,sulfonated acetone formaldehyde condensate, polycarboxylate ethers, orcombinations thereof, wherein the dispersant is present in an amount ofabout 0.01% to about 5% by weight in the mixture, and wherein themixture further comprises a viscosifying additive selected from thegroup consisting of organophilic clay, hydrophobically modified silica,hydrophobically modified bio-polymers, hydrophobically modifiedsynthetic polymers, or combinations thereof.